1. Field of the Invention
The present invention relates to apparatus for aspirating, irrigating and/or cleansing wounds, and a method of treating wounds and the exudates from such wounds using such apparatus for aspirating, irrigating and/or cleansing wounds.
The invention relates in particular to such an apparatus and method that can be easily applied to a wide variety of wounds, to cleanse them of materials that are deleterious to wound healing, whilst retaining materials that are beneficial in some therapeutic aspect, in particular to wound healing.
2. Background of the Invention
Before the present invention, aspirating and/or irrigating apparatus therefor were known, and tended to be used to remove wound exudate during wound therapy. In known forms of such wound therapy, the offtake from the wound, especially when in a highly exuding state, is voided to waste, e.g. to a collection bag or vessel which is removed when full and discarded as clinical waste. Materials deleterious to wound healing are removed in this way.
The volume of such exudates in some cases is very high and the collection bag or vessel can become relatively rapidly filled. If a collection bag or vessel of greater volume is used to extend the period between which the vessel needs to be emptied or changed this can have disadvantageous consequences on the portability of such apparatus and its convenience of use making the device or apparatus cumbersome and heavy. Furthermore, changing the collection bag or vessel is costly, time consuming and results in cessation of therapy.
In our co-pending International patent application, WO 2004/037334, apparatus, a wound dressing and a method for aspirating, irrigating and cleansing wounds are described. In very general terms, this invention describes the treatment of a wound by the application of topical negative pressure (TNP) therapy for aspirating the wound together with the further provision of additional fluid for irrigating and/or cleansing the wound, which fluid, comprising both wound exudates and irrigation fluid, is then drawn off by the aspiration means and circulated through means for separating the beneficial materials therein from deleterious materials. The materials which are beneficial to wound healing are recirculated through the wound dressing and those materials deleterious to wound healing are discarded to a waste collection bag or vessel.
In our co-pending International patent application, WO 2005/04670, apparatus, a wound dressing and a method for cleansing a wound using aspiration, irrigation and cleansing wounds are described. Again, in very general terms, the invention described in this document utilises similar apparatus to that in WO 2004/037334 with regard to the aspiration, irrigation and cleansing of the wound, however, it further includes the important additional step of providing heating means to control the temperature of that beneficial material being returned to the wound site/dressing so that it is at an optimum temperature, for example, to have the most efficacious therapeutic effect on the wound.
Our co-pending International patent application, WO 2005/105180, apparatus and a method for the aspiration, irrigation and/or cleansing of wounds are described. Again, in very general terms, this document describes similar apparatus to the two previously mentioned documents hereinabove but with the additional step of providing means for the supply and application of physiologically active agents to the wound site/dressing to promote wound healing.
There are available various forms of apparatus for topical negative pressure (TNP) therapy of wounds, the apparatus being intended to be portable and for use by a patient outside of hospitalisation, for example, in the home, outdoors or even at work so that the therapy can be continuously applied to a wound which does not necessarily require hospitalisation. In such apparatus, a vessel or canister is provided for receiving wound exudates, the canister being gradually filled by aspiration means such as a pump which applies a negative (below atmospheric) pressure. Eventually the canister becomes full and must be removed and discarded and a fresh, empty canister installed. Clearly, the less frequently this canister change is required the better.